Call her. Tell her she's beautiful. Don't let her put her make-up on. Sing to her. Play with her fingers. Teach her your favorite dance moves. Let her put make-up on you, just for a laugh. Let her take naps in your bed. Make sure she's comfortable without asking her if she is. Know she feels safe. Ask her to come over while your babysitting your younger siblings, so she can get a glimpse of what her future could be like with you. Love her. Make sure she knows you do. Don't let her forget it. Play pranks on her. Don't try too hard. Listen to her. Put forth effort into the conversation. Show her that it's not okay to give up, no matter what the situation. Miss her slowly. Hold her hand. Don't take advantage of her.
Never break her heart, because that's what she wants most.